I need help, I bought a um773 lite and I have a thunderbolt 3 to 2 then to FireWire adapters and I can't get it to work with the USB4 port under linux. Idk what bios setting to change. I have done everything I can on the Linux side.
I don't have much experience with Firewire sorry but with the double adapters in play, I believe you're facing a PCIe tunneling security issue. Check your BIOS to see if there are any Thunderbolt settings, or settings to allow or disallow PCIe tunneling. The next thing to check is whether the Thunderbolt devices are authorized in Linux.